Propeller log



Jan. 29, 1935. P. L.. MNSTER r-:r AL 1,989,332

PROPELLER LOG Filed Nov. 18,. 1931 l Il' j] l5 /0 /L-gf/ /NYEN faRS GYMM' Patented Jan. 29, 1935 PitoPELLERf LoG r Paul Lvegrsrn Mnster and oscar-Arbia riieim,

L Horteyn, orway 1 Application-November18,1931, serial No. f VIn Germany June 2, 1931 l 4 claims.

The invention relates to a propeller logl for electrical transmission to an indicating appara# tus on the bridge, in the chart-house or at; any other suitable place on the ship. l f

According to the invention the propeller vis ar#- ranged in a Pitot tube from which the driving water is conveyed to a discharge vtube which encloses or is arranged alongside the Pitot tubeand is closed at its upper end, Y

In order that the present invention may be the more readily understood reference is hereinafter made to the accompanying drawing show# ing a constructionalexample -ofthe prsent invention, Fig. 1 being a vertical section vthrough the log, Fig. 2 an upper end YView of the log and Fig. 3 a detail. Fig. 4 shows a modified form of the lower end of the log, and Fig. 5 is 'anenlarged sectional view of a portion of the structurev shown in Fig. 1. k

Referring to the drawing, 1 isaFitots tube with inlet 2, and 3 is the propellerarrangedina wider part which forms the propeller box or casing 4 in the upper part of the'Pitot tube. [The water flows over the upper edge of the Pitot tube to the discharge tube 5, arranged concentrically around the Pitot tube, and out through the -outlet 6 opening to the rear. I f

The log is disposed in a'tube 7 through which the log may beraised and lowered through the' bottom 8 of the ship, a sluice valve 9 being provided for closing thewater way'throughthe log! The tube 7 is provided witha stufiing box 10.

The position of ,the log in .thetube 7 may be adjusted by changing the spacing pieces 11 interposed between flange 12 on the log and a corresponding flange 13 on the tube. As shown by the dotted lines in Figure 1, the upper ends of these spacers may be threaded in the flange l2 and or" course turning the pieces will change the distance between the two flanges, the spacers being retained in the position at which they are adjusted by means of set screws 11'.

The discharge tube is closed at its upper end by a removable cover 14 in which the shaft 15 of the propeller 3 is mounted in a sleeve 16 which may be lled with oil or fat to exclude moisture and for lubricating. The cover is shaped so as to avoid eddy-making and givey smooth deflection of the water from the Pitots tube to the discharge tube. For instance the cover may be substantially conical or of toroidal shape so that the direction of flow of the water will be altered gradually.

The propeller shaft is at its upper end provided with a worm 22 engaging a worm wheel 26 mountfusraaniff d ed "in a' bracket 27 o nthe cover 14. Alongside of the-bracket?? is arranged an insulated`plate29.

(Figure5) holdingacontact spring ywhich comes linto contact with a: contact pinor arm 28 on the wheel 26f`for each revolution of'the same. The pin 28 is in contact with the; wheel and `thereby grounded. fTo the'contact spring '30 is by means of Athe contact screw `,31 connected acable'v 32 which leads to an'V indicating apparatuso'r a distance meter on the bridge 'or' in another suitable place. 'Y In` v'the' line between the said contact screw 31 and the indicatingapparatus is insertedv ausual elr'em'e'nt from "which the electro-magnet in thecountingdevice of thexap parat'us'ilgets its voltage at each -closingfoffthe circuit by the. contact betweenthev springfSO and the contactpin-'ZS on'the 'wheel 26.1. The indicating apparatus. may, besides registering the distance Vcovered?and/orsshowing the1 speed, also be adapted to'give a soundorlight'signal at each closing ofiz the circuit. l 1 l j Owing-to. the contact `device 'being arranged onthe top of'Y the apparatusrand'n'ot'in its sub-L merged vpa1`^t,'the error whichoften voccurs in pro# peller logsY owing toi"short-:circuitings causedfby the ingressofseawateris avoided. n. For: regulating vthe wateristreamand thereby the number ,of revolutionsrofz'the propeller,4 there is arranged in connectionwith the cover 14a ring throttle y; 17 co-operatingiv f :with corresponding openingslin an'extensioni o f the Pitotsr tube: The adjustment of; the throttle `is eifectedl by turning'the cover 14, to permit-whichithez cover is not fastened by through bolts or screws, but f saidoutlet openings 18 with a ange 21 by which it rests on the discharge tube and is secured against turning relatively to this tube by the pin screws 20.

If the log is to be used at much varying speeds of the vessel, irregularities in the water stream may arise at increasing speeds owing to the fact that the losses by impact and eddying of the water during its passage through the tube increase more than in proportion to the increase of speed. In order to compensate for these irregularities, there may be arranged, preferably at the points where the water flows from the Pitots tube to the discharge tube, automatic flap valves 24 as shown in Fig. 3, whichfvalves at lower yspeeds of the vessel serve to some degree to contract the water stream, but at increasing speed of the vessel, and consequently higher velocity of the water stream through the Pitots tube, are opened automatically and thereby give a larger cross section of the passage for the water. Such flap valves may be arranged in front of one more of the said openings, suitably infront of .one Aopening in the forward part :and rone yin the :afterpart of the tube.

Adjustment of the water stream also mayy be eifected in a simple manner by lowering or raising theA log in its guide in the ships bottom'rs'o'that the outlet 6 of the discharge tube is .more or less covered thereby or is fully exposed. Thisfmay be obtained by adjusting or changing the above mentioned screws or distance mieoes 111. IJrzetwieu'n the flange 12 of the log and the flange'lB -Io'flbhe supporting tube 7.

In the constructional form of the lower end of thelogs illustrated .in vfllig. 1, thewtube enclosingthe Pitot-s ltuloe is carried Vdown approximately sto-,the end of the .Pitots tube and both tubes are Vfastened toacasting ,1in which the inlet to -the Pitot-s tube ,is 1ar-rangedand` :in which there are formed ,guides-for `the .outlet of the water from the .outer tube. -This construction has :the iadvantage `that `the `outlet is ,located comparatively deep below :the :shipis .-bottom `wherefore the .effect of thedrag-ofg-the same upon `.the water is elimimated-so that the correction curves -of fthe flog become .more ihorizontal.- v 3 The arrangement fof the `propeller fhan'ging from, 'the 'cover @of fthefpropeller casing vgives fthe advantage that fthe propellerimay be reasily removedforinspectionwhen the'logfisgpulled infand the valve;9:o1osed. nAtthefsame itimeitlie tubemay easily be cleaned and :freed lfromfsea-weedfor the likeiwhichimayahaverentenedtthe itubethrough .the forward inletflopeningiz. v

'I'he widened propeller casingumakes it ipossible to iusefapropellerzcfafcomparatively largefdiameter 'working with fa '110W fnumber df revolutions whereby 1,wear :is reduced rand :a ancre .solid .iconstructionimade"ipossible, The resistance of lth'e transmission properiissreducedpartlyrbecause the low number :of revdlutionsfof .the prcpeller. makes it'possible rt'o `use lfewer wheels for lthe :driving lof, the .contact fdisdsnd ipartiy because tne prjessure cftlre ieethfof theworm wheeleagainst the worm on ithe propeller' shaftiandltne -dynarriic 'pressure uf the water `.butin-'act v'in ia" directioniopposed itc theweightiof the' fpiicpeller whereby the friction in the bearing of the propeller is reduced to a minimum.

' What we claim is:

1. A ships log, comprising in combination, a Pitot tube adapted to project through an aperture in the hull, a shaft coaxially disposed within the Pitot tube, a propeller mounted on said shaft, a discharge tube disposed concentrically about the Ptottubefa cover for the discharge tube spaced from 'the inner end of the Pitot tube, and means .disposed between the inner end of the Pitot tube 'and the cover for regulating the ow of water therebetween.

,2. A vships 10g, comprising in combination, a "Pitot Ltube adapted to project through an aperture in the hull, a shaft coaxially disposed within thesPitctitube,zaipropeller mounted on said shaft, ia. discharge tube disposed concentrically about the ,Pitot `tube, a cover for the discharge tube spaced from the inner end of the Pitot tube for deflecting .the -water from the Pitot tube into the discharge `tube, and fa ring valve located between the inner endof the #Pitot :tube and vthe -cover :for regulating the flow -.of water from the Pitot tube into thedischarge tube.

.3. ,A'ships flog, comprising in zcoinbination, ,a Bitottube adapted to vproject through an aperture in the hull, a ishaft coaxially-disposed within :the Pitot tube, a propeller suppcrtedon said shaft ads jacent athe linnerlendfof the tube, a discharge tube disposedA concentrically about ,the Pitot tube, a coverfor ithe-discharge .tube spaced from the inner end-of xthe Pitet'tube and formedftodeflect the Water from the ,Pitotitubefinto'the discharge tube, and outwardly opening flap Avalves 4for regulating bhesize of-the-outletfrom the vPitot-tube into the discharge tube, said valves 'being .located intermediate ithe inner `end `of the Pitot tube and =the cover.

:4. Alships log, :comprising in combination, a Pitot'ltubedaptedtoI-project 4through an laperitiue inthe hull, ashaft ,coaxially'disposed within .che Pitot tube, a rpropeller-supported-on said fshaftfa discharge -tube idisposed concentrically 'aboutl the Pitot tube,fa\cover.for.-said discharge 'tube spaced from .the inner .end of :the Pitot tube and formed to deflect the water from Vthe Pitot tube :into the discharge tube, :and :means :associated vwith said cover vand `disposed -between the inner-end of the Pitotltube and the Icover for regulating fthe fiiow of Water lbetween said tubes.

1-PAULrnvENRN MNSTER.

OSCARALBIN THELIN. 

